The Atlantic heaths

In western Scotland there is a series of oceanic heaths which have a
very interesting moss and liverwort flora. These bryophyte-rich
heaths are usually limited to steep and rocky slopes on the north or
north-east side of the hills, with heather dominant on the lower slopes
and blueberry becoming more frequent higher up. Under the dwarf
shrubs is a thick mat of bryophytes in which species of Sphagnum are
common. But it is the large, leafy liverworts that provide the
interest, often forming swelling cushions of brown, orange and red.

There are a number of uncommon species here which have an extraordinary
world distribution in a number of disjunct (widely separated)
localities.

The best stands of this heath are in the north-west with good examples
on the remote Sutherland hills and the mountains of Torridon, where
Beinn Eighe has the only British population of Northern prongwort
Herbertus borealis. What all these sites have in common is
a climate in which long, dry spells are rare and frost is infrequent
and there has been little disturbance in recent times. The
protection given by the cover of heather or blaeberry seems to be
critical and without it these plants are limited to areas of block
scree or moderate snow-lie.

Recent survey work in the Hebrides has also revealed that an endemic
species of Sphagnum also regularly occurs in this community. Skye
bog-moss Sphagnum skyense was first described from Skye but it is also
frequent on Rum and in the Harris hills. It often occurs with
another near-endemic species Silky swan-neck moss Campylopus setifolius
which, outside western Britain and Ireland, is only known from one site
in north-west Spain.

In European terms, extensive stands of this oceanic heath community are limited
to the west of Britain and Ireland, with the greatest extent on the mountains
of the north-west of Scotland. We have a particular responsibility
for it, though it has been overlooked in conservation terms.